/*
 * LabelMap.java July 2006
 *
 * Copyright (C) 2006, Niall Gallagher <niallg@users.sf.net>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

package wx.xml.simpleframework.xml.core;

import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Set;

/**
 * The <code>LabelMap</code> object represents a map that contains
 * string label mappings. This is used for convenience as a typedef
 * like construct to avoid having declare the generic type whenever
 * it is referenced. Also this allows <code>Label</code> values
 * from the map to be iterated within for each loops.
 *
 * @author Niall Gallagher
 * @see wx.xml.simpleframework.xml.core.Label
 */
class LabelMap extends LinkedHashMap<String, Label> implements Iterable<Label> {

    /**
     * This is policy used to determine the type of mappings used.
     */
    private final Policy policy;

    /**
     * Constructor for the <code>LabelMap</code> object is used to
     * create an empty map. This is used for convenience as a typedef
     * like construct which avoids having to use the generic type.
     */
    public LabelMap() {
        this(null);
    }

    /**
     * Constructor for the <code>LabelMap</code> object is used to
     * create an empty map. This is used for convenience as a typedef
     * like construct which avoids having to use the generic type.
     */
    public LabelMap(Policy policy) {
        this.policy = policy;
    }

    /**
     * This allows the <code>Label</code> objects within the label map
     * to be iterated within for each loops. This will provide all
     * remaining label objects within the map. The iteration order is
     * not maintained so label objects may be given in any sequence.
     *
     * @return this returns an iterator for existing label objects
     */
    public Iterator<Label> iterator() {
        return values().iterator();
    }

    /**
     * This performs a <code>remove</code> that will remove the label
     * from the map and return that label. This method allows the
     * values within the map to be exclusively taken one at a time,
     * which enables the user to determine which labels remain.
     *
     * @param name this is the name of the element of attribute
     * @return this is the label object representing the XML node
     */
    public Label getLabel(String name) {
        return remove(name);
    }

    /**
     * This is used to acquire the paths and names for each label in
     * this map. Extracting the names and paths in this manner allows
     * a labels to be referred to by either. If there are no elements
     * registered with this map this will return an empty set.
     *
     * @return this returns the names and paths for each label
     */
    public String[] getKeys() throws Exception {
        Set<String> list = new HashSet<String>();

        for (Label label : this) {
            if (label != null) {
                String path = label.getPath();
                String name = label.getName();

                list.add(path);
                list.add(name);
            }
        }
        return getArray(list);
    }

    /**
     * This is used to acquire the paths for each label in this map.
     * Extracting the paths in this manner allows them to be used to
     * reference the labels using paths only.
     *
     * @return this returns the paths for each label in this map
     */
    public String[] getPaths() throws Exception {
        Set<String> list = new HashSet<String>();

        for (Label label : this) {
            if (label != null) {
                String path = label.getPath();

                list.add(path);
            }
        }
        return getArray(list);
    }

    /**
     * This method is used to clone the label map such that mappings
     * can be maintained in the original even if they are modified
     * in the clone. This is used to that the <code>Schema</code> can
     * remove mappings from the label map as they are visited.
     *
     * @return this returns a cloned representation of this map
     */
    public LabelMap getLabels() throws Exception {
        LabelMap map = new LabelMap(policy);

        for (Label label : this) {
            if (label != null) {
                String name = label.getPath();

                map.put(name, label);
            }
        }
        return map;
    }

    /**
     * Convert a set in to an array. Conversion is required as the keys
     * and paths must be arrays. Converting from the set in this manner
     * helps the performance on android which works faster with arrays.
     *
     * @param list this is the set to be converted to an array
     * @return this returns an array of strings from the provided set
     */
    private String[] getArray(Set<String> list) {
        return list.toArray(new String[]{});
    }

    /**
     * This method is used to determine whether strict mappings are
     * required. Strict mapping means that all labels in the class
     * schema must match the XML elements and attributes in the
     * source XML document. When strict mapping is disabled, then
     * XML elements and attributes that do not exist in the schema
     * class will be ignored without breaking the parser.
     *
     * @param context this is used to determine if this is strict
     * @return true if strict parsing is enabled, false otherwise
     */
    public boolean isStrict(Context context) {
        if (policy == null) {
            return context.isStrict();
        }
        return context.isStrict() && policy.isStrict();
    }
}
